<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0px;
            margin: 0px;
        }
        body {
            display: flex;
            justify-content: center;
        }
        .wrap {
            width: 80%;
            height: 600px;
            border: 1px solid black;
        }
        .box1 {
            width: 100px;
            height: 200px;
            background: rgb(230, 71, 79);
            float: left;
        }
        .box2 {
            width: 100px;
            height: 200px;
            background: rgb(141, 208, 245);
            float: left;
        }
        .box3 {
            width: 100px;
            height: 200px;
            background: rgb(241, 244, 78);
            float: right;
        }
        .content{
            clear: both; /*清除浮动clear: left/right/both*/
        }
    </style>
</head>
<body>
    <div class="wrap">
        <h1>浮动定位 float : left / right</h1>
        <div class="box1"></div>
        <div class="box2"></div>
        <div class="box3"></div>
        <p class="content">正常内容</p>
    </div>
</body>
</html>